Google Cloud Messaging (GCM)

Steps to do before:

If you haven’t created the API project yet, click CREATE PROJECT. Give the name of the project and click Create.

Note down the project number. You will use the project number as sender ID in the registration process.

In the sidebar on the left, click APIs and auth. In the displayed list of APIs, turn the Google Cloud Messaging for Android toggle to ON.

In the sidebar on the left, click APIs and auth and Credentials.

Click CREATE NEW KEY and select Server Key.

Provide the list of IP address from which the GCM server accepts the request. Left blank if you want to allow any IP. (Its recommended to provide IP address, so that anyone won’t access to it but for this tutorial purpose i left it blank.).